In RAM Frame does it assume that brace does not provide any support to determine the gravity load in the beam?
The brace does provide support in Ram Frame, though tension-only braces are discounted for gravity loads. See: https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/6513/ram-ss---analysis-types-tn
and
https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/3058/ram-frame---tension-only-faq